So that's the rank that comes after G-Rank, huh? Isekai-Rank. Otherworld-Rank. Reincarnation-rank? I-Rank? OW-Rank? R-Rank? Hmmm, G-Rank itself was just chosen because it sounded cool, or so I've heard, so eh. I like Otherworld-Rank personally. Sign me up!
Oh, except it wouldn't be like a low rank > high rank, or a high rank > G-rank, because it'd likely be a whole new world with new monsters. Hmmm. . .